Electrical counting or distributing circuits



Sept. 9, 1958 f Filed Oct, 26, 1955 J. H. BEESIIEY ELECTRICAL COUNTING OR DISTRIBUTING CIRCUITS 3 Sheets-Sheet 1 nnnnn o ""1"" Fig. 1

IT'TORNEY SePt 1958 J. H. BE SLEY ELECTRICAL CQUNTING OR DISTRIBUTING CIRCUITS Filed Oct. 26, 19 55 VIII""' ITTORNEY United States Paten 2,851,636 ELECTRICAL COUN'IENGOR DISTRIBUTING CIRCUITS John Henry Beesley, Coventry, England, assignor to The General Electric Company Limited, London, England Application 'October 26,1955, Serial No. 542,991

Claims priority, application Great Britain October 28, 1954 11 Claims. (Cl. 31584.5)

This invention relates to electrical counting or distributing circuits of the kind which employ a plurality of gas discharge tubes each having an anode and a cathode forming a main discharge gap and a trigger electrode forming an auxiliary discharge gap with the cathode. The invention is more particularly concerned with such circuits in which the counting or distributing stages are arranged in a continuous chain, sometimes referred to a ring-connected circuit, and which have a plurality of input paths to which the electrical signals to be counted or distributed are applied.

it has been proposed in my copending U. S. patent application No. 486,237, filed February 4, 1955, for Electrical Gas Discharge Tube Circuits to provide a circuit which comprises a plurality of gas discharge trio'des and two input leads. Each t'riode is provided with aconnection from its cathode circuit to the trigger electrode circuit of the next succeeding gas triode so as to form a ring-connected circuit. A different connection is taken from one of the input leads to the trigger electrode circuit of every alternate gas triode, the intervening gas triodes being similarly connected to the second input lead. It is arranged that when one of the gas "triodes is conducting across its main discharge gap a voltage is developed at its cathode which is of suflicientv'alue "to initiate an auxiliary gap discharge in the succeeding 'tube.

The circuit-is however such that this voltage is not applied across the said anxiliariy gap until a suitable voltage signal to be counted or distributed is applied to the appropriate one of the input leads, the said voltage signals being applied alternately to the two input leads.

It is an inherent feature of such circuits that the striking of any one gas tube is always initiatedby the occurrence of an electrical signal on the same input lead so that if every suitable signal that is applied to the input leads is to be counted or distributed the number of counting or distributing stages must be a multiple of the number ofin'put leads.

it is an object of the present invention 'to provide im- "proved electrical counting or'dis'tfibuting circuits of the kind specified.

According to the present invention an electrical counting or distributing circuit includes a Small plurality of input leads and a plurality "of gas discharge tubes which each has an anode, acathode and a trigger electrode and which are connected in a ring, the arrangement being such that a striking voltage may be applied between the trigger electrode and cathode of the second gas tube of a pail-of gas tubes that occupy "succeeding positions in the ring when, during one counting or distributing cycle of the ring, the first gas tube of the said pair is conducting and at least a predetermined voltage occurs on a particular one of the input leads in consequence of an input signal to be counted or distributed and, during the next succeeding counting or distributing cycle of the ring, the first gas tube of the said pair is conducting and 'at least a.

predetermined v'olta'g'e occurs on a different one of the input leads in consequence of an input signal to be counted or distributed. v I

According to one feature of the present invention an electrical counting or distributing circuit comprises a plurality of gas discharge 'tub'e's connected in a ring, a plurality of signal gating circuits each having first, second and third inputs and an output, the first gas tube of each pair of gas tubes that occupy succeeding positions in the ring having its cathode connected both to the first inputs of a small plurality of said signal gating circuits and to resistance means for deriving a striking voltage from the discharge current that flows when that first gas tube is conducting, a small plurality of input leads, a plurality of paths, the second inputs of said small plurality of signal gating circuits being connected each to a different one of the input leads, 'the third inputs ofsaid small plurality of signal gating circuits being connected each to a different one of said paths and the outputs of said small plurality of signal gating circuits being connected to the trigger electrode of the second gas tube of the pair, and means which is adapted to be controlled by one or more of the said gas tubes of the ring and which is operable to apply voltage signals to the said paths in a predetermined sequence, the arrangement being such that the second gas tube ota pair may strike only when the first gas tub'e dfthatpair is conducting and voltage signals occur simultaneously on the second and the third inputs of one of the small plurality of signal gating circuits associated with that pair of gas tubes.

Preferably the last said means comprises a further plurality of gas discharge tubes which are connected in a ring and which are associated each with a different one of the said paths, each of the gas tubes of the said further plurality being adapted so that When conducting a voltage signal is applied 'to the associated path and the arrangement being such that the gas tubes of said further plurality may be struck in sequence, one at a time, under the controlof one or more of the gas tubes of the first said plurality.

. One arrangement of an electrical counting circuit in accordince with the present invention will now be described, by way'of example, with reference to the three figures of the accompanying diagrammatic drawings in which:

Figures land 2 show complementing parts of the counting circuit, these figures beinglaid side by side with the right-hand edge 'of Figure 1 against the left-hand edge 'of Figure 2 to show the complete circuit,

Figure 3 is a chart showing the sequence of opt-cations of the counting circuit illustrated in Figures 1 and 2, and

Figure 4 shows an alternative input circuit for the counting circuit.

The circuit shown in Figures 1 and 2 comprises an input circuit 50 conneoted between input terminals 44 and 45 and two input leads 1 and 2, a first ring of five gas discharge tubes 37-, a second ring of four gas discharge tubes 8-11 and a plurality of signal gating circuits. Each of the gas discharge tubes 351-1 has an anode 12, a cathode 13 and a trigger electrode 14 and is "of the cold "cathode type.

The "gas triode's 3-7 of the first ring have their anodes 12 connected to a common lead 15 and thence by way of a resistor 16 we terminal 17. Similarly the gas triodes 8-11 of the second ring have their anodes 12 connected to a common lead 18 and thence by way of a resistor 19 to a terminal 20. During operation of the counting circuit the terminals 17 and 20 are maintained at a positive potential with reference to earth, hereinafter referred to as the H. T. potential. The value of the T. potential is such that when one of the gas triodes 3 11 is triggere'd, that is a discharge is initiated between its trigger ,to earth by way of a parallel resistance capacitance network, such as the network" that is associated with gas triode 3 and which comprises in one arm a resistor 21 and in the other arm a capacitor 22 and a resistor 23 in series. The value of each resistor such as the resistor 21 is such that when the associated gas triode, as for example the gas triode 3, is conducting the cathode 13 of that triode attains a positive voltage with respect to earth by virtue of the discharge current. The value of this voltage is sufficient to trigger the succeeding gas triode 4 when applied, as hereinafter described, across the trigger electrode to cathode gap of that tube.

Each of the gas triodes 3-7 has its cathode 13 connected to the trigger electrode 14 of the succeeding gas triode by way of two similar gating circuits. Thus the two gating circuits which connect the cathode 13 of the gas triode 3 to the trigger electrode 14 of the gas triode 4 each comprise a resistor 24 or 25 and rectifier elements 26, 28 and 29 or 27, 35 and 36 respectively. In these gating circuits the resistor 24 or 25 and the rectifier element 26 or 27 respectively are connected in series and in that order between the said cathode and the said trigger electrode. The junction of the resistor 24 and the rectifier element 26 is connected to the input lead 2 by way of the rectifier element 28 and to the lead 30 by way of rectifier element 29, both of the rectifier elements 28 and 29 being connected so as to be conductive to conventional current flow away from the said junction to their respective leads 2 and 30. The junction of the resistor 25 and the rectifier element 27 is similarly connected by way of rectifier elements 35 and 36 to the leads 1 and .32 respectively. The input leads 1 and 2 are connected rectifier elements are biased so as to be non-conducting. .The voltage applied over the rectifier element 26 or 27 to the trigger electrode 14 of the gas triode 4 will thus be less than the voltage at the cathode 13 of the gas triode 3 by an amount substantially equal to the voltage drop which results across the resistor 24 or 25 due to the said electric current. Thus the voltage developed at the cathode of gas triode 3 when conducting can only trigger the gas triode 4 upon the simultaneous occurrence of positive voltages on the leads 2 and 30 or on the leads 1 and 32, these voltages being of sufiicient value to bias the rectifier elements 28 and 29 or the rectifier elements 35 and 36 so as to be non-conducting.

That part of the arrangement which is associated with the gas triodes 8-11 forms a distributing circuit of the kind described in the specification of my copending U. S. patent application No. 486,237, filed February 4, 1955, for Electrical Gas Discharge Tube Circuits. Thus the gas triodes 8-11 are arranged to strike in sequence, one at a time, in response to voltage signals that are applied alternately to the leads 37 and 38, these leads being connected by way of rectifier elements 39 and 40 to the cathode 13 of the gas triodes and 7 respectively. When one of the gas triodes 8-11 is conducting the voltage that is developed at its cathode 13 is applied by way of a rectifier element to the appropriate one of the leads 30 to 33, these leads being associated each with a different one of the gas triodes 8-11.

The operation of the circuit will now be described in its application to the counting of electrical pulses that are applied alternately to the input terminals 44 and 45 and thence by way of rectifier elements 46 and 47 of the ,below the discharge maintaining value.

4- input circuit 50 to the input leads 1 and 2. The resulting voltage pulses on the input leads 1 and 2 are positive with respect to earth and of sufficient amplitude to bias to a non-conducting condition each of the rectifier elements, such as the rectifier elements 28 and 35, that are connected to the input leads 1 and 2.

Let it be assumed that the gas triodes 3 and 8 are conducting and that the first pulse to be counted is applied to the input terminal 45. The positive voltage at the cathode of the gas triode 8 is applied by way of rectifier element 34 to the lead 30 and biasses the rectifier element 29 so as to be non-conducting. On application of the first pulse to be counted to the terminal 45, the input lead 2 attains a positive voltage with respect to earth so that the rectifier element 28 is similarly biassed.

Consequently the voltage of the cathode 13 of the gas triode 3 is applied to the trigger electrode 14 of the gas triode 4 by way of the resistor 24 and the rectifier element 26. On the gas triode 4 striking, its discharge current flows through the common resistor 16. The resulting fall in voltage of the common lead 15 is such as to reduce the anode to cathode voltage of gas triode 3 The discharge in gas triode 3 is thus extinguished, whereafter the voltage on lead 15 again rises to its initial value. This tempor'ary fall in anode voltage does not however prevent the dis-charge in gas triode 4 from becoming established as the cathode voltage of this tube rises relatively slowly from earth potential.

. Application of the second pulse to be counted to the terminal 44 results in the rectifier element 41 being .biassed to a non-conducting condition so that the gas triode 5 is triggered by the voltage on the cathode of the gas triode 4.

On the gas triode 5 striking, the gas triode 4 is extinguished in the manner previously described. The voltage developed at the cathode 13 of gas triode 5 is applied by way of rectifier element 39 to the lead 37 and is of sufficient value to bias the rectifier elements 42 and 43 to a non-conducting condition. The gas triode 9 is consequently triggered by the voltage at the cathode 13 of .gas triode 8. On the gas triode 9 striking the gas triode 8 is extinguished in a similar manner to that described .above in connection with gas triode 3, and the positive voltage that is developed at the cathode of gas triode 9 and results in the striking of gas triode 7 with the consequent extinction of the discharge in gas triode 6. The

positive voltage that is developed at the cathode of triode 7 is applied by way of rectifier element 40 to the lead 38 and results in the striking of gas triode 10 with .the1 consequent application of a positive voltage to the lead 32. The subsequent extinction of the discharge in gas triode 9 results in the removal of the positive voltage fromthe lead 31.

Thecount thus proceeds in accordance with the chart jshown in Figure 3, in which the same reference numerals are employed for the gas triodes and for the input terminals as in Figures 1 and 2. In Figure 3 a conducting gas triode 3-11 is indicated by an X. This indication is also employed to signify which of the two input terminals44 or 45 receives an input pulse to be counted. From the chart it will be seen that each condition of the circuit is repeated at intervals of ten input pulses.

Thus the input pulse numbers 1 and 11 are both applied to terminal 45 and each result in the striking of gas triode 4 of the first ring, the gas triode 8 of the second Iing being then conducting. It will also be apparent that each gas triode 37 of the first ring is struck twice during enemas a sequence of ten input pulses as the result of input pulses applied each to a different input terminal 44 or 45.

Although in the arrangement described above two input leads have been employed it should be understood that the invention is not restricted to this number. Thus the circuit shown may be readily modified to cater for three input leads by providing three signal gating circuits between adjacent stages in the said first ring and employing six distributing stages in the said second ring.

A further modification of the circuit illustrated and described above may be made as follows:

The input circuit 50 which, in Figure 1, comprises the rectifier elements 46 and 47 and resistors 48 and 49 is replaced by the input circuit 50 shown in Figure 4. Thus the input leads 1 and 2 are each connected to earth, or whatever other reference potential is employed, by way of a difierent path. Each of these paths includes a set of contacts X1 or Y1 that are normally closed and a resistor 51 or 52. Each set of contacts X1 and Y1 is, for example, associated with a different electromagnetic relay X or Y, it being desired to register the operations of the two said relays X and Y that occur alternately.

Let it be assumed that the gas triodes 3 and 8 are conducting and that both sets of contacts X1 and Y1 are closed. The leads It and '2 are at earth potential, as applied over said contacts, and the gas triode 4 cannot strike since its trigger electrode 14 is held substantially at the voltage of the lead 2. If the contacts Y1 associated with the lead 2 are opened momentarily, the voltage of that lead 2 rises to the voltage at the cathode 13 of the gas triode 3 and the gas triode 4 therefore strikes. lf then the contacts X1 associated with the lead 1 are opened momentarily the voltage of lead 1 rises to that of the cathode of the gas triode 4 and the gas triode 5 strikes. Succeeding operations of the said contacts X1 and Y1 are thus registered by the circuit which functions in the manner previously described.

l claim:

1. An electric pulse counting circuit including a first gas tube ring and a second gas tube ring, each said ring employing a plurality of gas tubes each of which has an anode, a cathode and a trigger electrode, said tubes being connected for mutual extinguishing action so that upon the conduction of any one of the gas tubes the anode to cathode discharge in any previously conducting gas tube of the same ring is extinguished; said first ring comprising a lesser plurality of input leads than gas tubes to which input leads striking voltages, eachthe result of a separate pulse to be counted, are applied, the number of input leads not being a sub-multiple of the number of gas tubes of the first ring, an individual resistance connected to the cathode of each gas tube to derive a striking voltage from the anode to cathode discharge current through that gas tube when conducting, and a separate plurality of first gating devices between each pair of gas tubes that occupy consecutive positions in the first ring, each said plurality of first gating devices being equal in number to the input leads and each first gating device having an output connected to the trigger electrode of the second gas tube of the associated pair, a first input connected to the cathode of the first gas tube of the associated pair, a second input and a third input, each first gating device being adapted to gate a striking voltage to the output to render the said second gas tube conducting only upon the co incidence of at least the striking voltage of all three of the said inputs, said first ring being divided into separate parts, each said part comprising at least two consecutive gas tubes together with said first gating devices having their outputs connected to those gas tubes; said second ring comprising a number of gas tubes equal to the product of the number of said parts and the number of said input leads, an individual resistance connected to the cathode of each gas tube to derive a striking voltage from the anode to cathode discharge current through that gas tube when conducting, a separate path connected to the cathode of each gas tube, a'se'paratecontrol-lead connected to the cathode of the last gas-tube or each part of said first ring and a second gating device between each pair of gastubes that occupy 'consecutive'positions in the second ring, each second gating device interconnecting the cathode of the first gas tube of the associated pair, the trigger electrode of the second gas tube of that pair and an associated one of the said control leads, each second gating device being adapted to gate a striking voltage to the trigger electrode of the second gas tube of the associated pair to render that gas tube conducting only upon the coincidence-of at least the striking voltage at the particular cathode and the particular control lead connected to the second gating device, succeeding gating devices being connected to the control leads in accordance with the same sequence as said parts associated with the control leads occur in said first ring so that consecutive second gating devices are associated respectively with consecutive parts and so that each said control lead is connected to a number of the second gating devices equal to the input leads, the separate plurality of first gating devices between each said pair of gas tubes having their second inputs each connected to a different one of the input leads and their third inputs connected individually one to each of those of the said paths that are connected to those of the said second gating devices which, in turn, are connected to the particular control lead associated with the part of-said first ring in which the separate plurality of first gating devices occurs, no first gating devices in consecutive positions in the first ring having their second and third inputs connected to the same path and to the same input lead.

2. A circuit according to claim 1 wherein the first and second rings each have positive and negative terminals for connection to the positive and negative sides respectively of power supply means, a common rail connected to the anodes of all the gas tubes of the ring and common resistance connected between the positive terminal and the common rail of the ring, and wherein each of the individual resistances is connected between the cathode of the associated .gas tube and the negative terminal of the appertaining ring, there being provided individual capacitance means connected in shunt with each said individual resistance, and in each said ring, the said common resistance, the said individual resistances and the said individual capacitance means acting upon the supply of a suitable potential difference between the said first and second terminals to provide said mutual extinguishing action between the gas tubes.

3. A circuit according to claim 1 wherein there are provided positive and negative terminals to apply positive and negative potentials to the gas tubes, a separate set of normally closed contacts for each of the input leads and contact actuating means which is responsive to pulses to be counted being supplied thereto in a recurring sequence to open said sets of contacts one for each pulse and according to said recurring sequence, each individual resistance being connected between the cathode of the associated gas tube and said negative terminal, each said set of contacts being connected between the associated input lead and said negative terminal and each first gating device providing a connection between the associated cathode and input lead whereby conventional current flow may occur from that cathode to that input lead.

4. A circuit according to claim 3 wherein separate resistance means is connected in series with each set of contacts to limit the current which may flow through those contacts.

5. A circuit according to claim 4 wherein the contact actuating means comprises a separate electromag netic relay for actuating each set of contacts, each relay having an operating winding, and the electric pulses to be counted being supplied to said operating windings in a recurring sequence.

6. A circuit according to claim 1 wherein each first gating device comprises a resistance connected in series with a first rectifier means and in that order between the first input and the output, a second rectifier means connected between the second input and the junction of said resistance and said first rectifier means, and a third rectifier means connected between the third input and the said junction, said first, second and third rectifier means being each so poled as to be in the direction of easy conductivity for current flowing from said junction to the output and to said second and third inputs respectively of the gating device.

7. A circuit according to claim 1 wherein each second gating device comprises a resistance connected in series with a first rectifier means and in that order between the cathode and trigger electrode of the first and the said second gas tubes respectively of the associated pair, and a second rectifier means connected between the associated control lead and the junction of said resistance and said first rectifier means, the said first and second rectifier means being each so poled as to be in the direction of easy conductivity for current flowing from the said junction to said trigger electrode and to said control lead respectively.

8. A circuit according to claim 1 wherein the gas tubes are cold cathode gas discharge triodes.

9. An electric pulse counting circuit having a first gas tube ring and a second gas tube ring, each said ring employing a plurality of gas tubes each of which has an anode, a cathode and a trigger electrode, said tubes being connected for mutual extinguishing action so that, upon the conduction of any one of the gas tubes, the anode to cathode discharge in any previously conducting gas tube of the same ring is extinguished; said first ring comprising an odd number of gas tubes, two input leads to which striking voltages, each the result of a separate pulse to be counted, are applied, an individual resistance connected to the cathode of each gas tube to derive a striking voltage from the anode to cathode discharge current through that gas tube when conducting and two first gating devices between each pair of consecutive gas tubes, each first gating device having an output connected to the trigger electrodeof the second gas tube of the associated pair, a first input connected to the cathode of the first gas tube of the associated pair, a second input and a third input, each first gating device being adapted to gate a striking voltage to the output to render the said second gas tube conducting only upon the coincidence of at least the striking voltage on all three of the said inputs, said first ring being divided into two separate parts, each said part comprising at least two consecutive gas tubes together with said first gating devices having their outputs connected to those gas tubes; said second ring comprising four gas tubes, an individual resistance connected to the cathode of each gas tube to derive a striking voltage from the anode to cathode discharge current through that gas tube when conducting, a separate path connected to the cathode of each gas tube, a separate control lead connected to the cathode of the last gas tube of each said part of said first ring and a second gating device between each pair of consecutive gas tubes of said second ring, each second gating device interconnecting the cathode of the first gas tube of the associated pair, the trigger electrode of the second gas tube of that pair and an associated one of the said control leads, each said second gating device being adapted to gate a striking voltage to the trigger electrode of the second gas tube to render that gas tube conducting only upon the coincidence of at least the striking voltage at the particular cathode and the particular control lead connected to the second gating device, alternate second gating devices being connected to the same said control lead, and the said two first gating devices between each said pair of gas tubes having their second inputs each connected to a different one of the input leads and their third inputs connected individually one to each of those of the said paths that are connected to those of the said second gating devices which, in turn, are connected to the particular control lead associated with the part of said first ring in which the two first gating devices occur, no first gating devices in consecutive positions in the first ring having their second and third inputs connected to the same said path and to the same said input lead.

10. An electric pulse counting circuit according to claim 9 wherein any two consecutive first gating devices which each occur in a different one of the parts of the first ring and which have their second inputs connected to difierent ones of the input leads have their third inputs connected to those of the paths that are connected to consecutive gas tubes of the second ring so that the particular one of those first gating devices occupying the more advanced position in said first ring is associated with the particular one of those gas tubes occupying the more advanced position in the second ring.

11. A circuit according to claim 10 wherein the gas tubes are cold cathode gas discharge triodes.

References Cited in the file of this patent UNITED STATES PATENTS 2,379,093 Massonneau June 26, 1945 2,719,227 Gordon Sept. 27, 1955 2,722,630 Branch et al. Nov. 1, 1955 

